Optoelectronic devices, such as transponders, may require RF integrity (i.e., avoiding electrical shortages in the device), hermetical sealing (i.e., a technique of making a material impervious to air and/or fluids by fusion), thermal dissipation (i.e., drawing away heat generated by the device to avoid overheating) or selective plating (i.e., a technique to deposit different metals and/or alloys on conducting materials). Currently, for example, substrate selective plating is performed manually by applying an inert mask material to selected metal surfaces or patterns. To illustrate this concept, a first metal surface may need nickel (Ni) plating while a second metal surface may need gold (Au) plating. In particular, the process may begin with masking the second metal surface with an inert paste (i.e., cover the second surface with the inert paste) while the first metal surface may be plated by nickel. The inert paste may be cleaned off to the second metal surface. Accordingly, the first metal surface may then be covered by an inert paste while the second metal surface may be plated by gold. Afterward, the inert paste may be cleaned off the first metal surface. The first and second metal surfaces may be plated differently but the process involved may be inefficient, expensive and may introduce impurities into the various plating. For example, laser welding performed on a nickel-plated pattern may result in cracks due to gold impurities introduced in the nickel plating.
Optoelectronic devices may further require thermal dissipation to disperse heat that may be generated by optoelectronic devices formed on top of a substrate. Currently, for example, optoelectronic devices may be formed on a ceramic substrate. The ceramic substrate may include thermal vias to dissipate heat generated by the optoelectronic device. However, thermal vias may be inefficient for optoelectronic devices that require high thermal dissipation.
Therefore, a need exists for an efficient, low-cost means to provide selective plating or different plating as well as efficient thermal dissipation while avoiding RF interference and maintaining a hermetic seal.